The present invention relates generally to a pivotal surfboard fin assembly for use on a surfboard.
Surfing requires a high level of adaptability to weather, tide, wave and other environmental conditions to a degree not found in most other sports. As with the weather, surf conditions can be somewhat difficult to precisely predict and are dynamic, requiring the surfing enthusiast be prepared for a wide range of wave conditions. A change in the size, direction, break, interval, and shape of waves necessitates that a surfer have access to surfing equipment adaptable to the dynamic state of wave conditions.
Of particular importance is the adaptability of the surfboard scags or fins to the predominating wave conditions at any given time. Depending on the characteristics of a wave, a surfer may want their surfboard to have either increased or decreased maneuverability on the face of a wave. This may be achieved by either increasing or decreasing the level of resistance the fin blades on a surfboard have to water forces. For example, on a larger wave with less shape, a surfer may prefer less maneuverability across the face of a wave, thereby requiring a fin that is more resistant to the water forces acting on the fin blade. When waves are perhaps smaller in size but have better shape, a surfer may require a surfboard with a fin blade having greater flexibility and therefore less resistance to water forces acting on the fin blade, thereby enabling the surfboard to alter direction quicker on a shorter turning radius. A surfboard fin assembly that is able to quickly and efficiently adjust the pivot of the surfboard fin may be useful for surfers desiring to be prepared for and able to adapt to ever changing wave conditions.
There are a number of surfboard fin assemblies that attempt to adjust the level of pivot of the surfboard fin in response to wave conditions, depending on the desired level of maneuverability. Many of these assemblies do not appear to be intended for use on surfboards, but rather appear to be intended for other water craft. Some of these prior art fin assemblies appear to allow a limited range for the pivoting of the surfboard fin, but do not enable the surfboard fin to not have any pivotal movement. Also, many of these prior art assemblies appear to be disposed in the interior of the fin blade, thereby encumbering access to the pivoting mechanism for adjustment of the surfboard fin's pivot. It is also understood that these prior art assemblies generally allow adjustment of the surfboard fin's pivot, but they do not appear to allow for the precise adjustment of the fin blade's pivot within a narrow range of motion.
For instance, U.S. Pat. No. 6,053,789 is understood to disclose a surfboard fin pivoting mechanism having a surfboard fin divided into two sections, an upper stationary mounting portion and a lower pivoting fin, with a rotational pivoting mechanism located in a recessed area in the leading edge of the lower pivoting fin. The pivoting mechanism is comprised of an upper and lower plate, with two pins located in the lower plate projecting into two cavities spaced in the upper plate, the range of motion being set by the boundaries of the cavities serving as a stop to prevent further pivot by the lower plate pins. A center stem projecting into the upper stationary mounting portion of the fin and a center stem projecting into the lower pivoting fin positions the pivoting mechanism. The lower plate pins project into the upper plate cavity and enable pivoting about the vertical axis of these lower plate pins. In another embodiment, it is understood that the pivoting mechanism appears to be located entirely in a base positioned in the surfboard with a cavity whose dimensions again determine the boundaries for pivotal range of motion. Two winged stops project into this cavity whose rotation about a vertical axis enables pivotal movement of the surfboard fin. Neither of these embodiments appear to provide for a surfboard fin having no pivotal range of motion. Furthermore, neither of these assemblies appear to have a pivoting mechanism that is readily accessible, thereby making the adjustment process more time consuming and less efficient. Finally, it is understood that both of these embodiments appear to allow the surfboard fin to pivot within a specific range of degrees determined by the dimensions of the prefabricated cavities. However, if a “fine-tuned” and precise pivotal range of motion is desired within a narrower range of motion, these embodiments do not appear to satisfy that objective.
It is understood that U.S. Pat. No. 4,733,496 discloses a pivoting surfboard fin intended for all types of water craft, allegedly including surfboards, that include a fixed blade portion attaching to the “vessel.” Two pivot pins located between the fixed blade and the pivot fin enable rotation about a vertical axis. A third foil pin positioned above a spring and a single threaded rod with an accompanying threaded thumbwheel provide a vertical stop mechanism. Precision adjustment of the pivoting mechanism in this fin blade assembly does not appear possible, particularly when used on a surfboard. In fact, it does not appear that the pivoting mechanism, fixed blade, and pivot fin aspects of the assembly would be suitable for use on a surfboard, in light of the splitting of the fin blade, the location of the pivoting mechanism, and the dimensions of the depicted assembly.
It is understood that U.S. Pat. No. 5,813,890 discloses a pivoting fin with elastic bias assembly for mounting to the lower surface of a watercraft hull. In one embodiment, a rectangular base is connected by hinge pins to a fin. This assembly appears to have a stop mechanism consisting of side springs and side shoulders that limit the pivot range of motion. Pivotal rotation appears to occur about a horizontal axis between the base and fin. The pivoting mechanism is located between a fixed fin portion extending from the mounting base and a pivoting fin section pivotally hinged to the fixed fin. The pivoting fin appears to contain a pair of tabs projecting into slots located in the fixed fin portion with shoulders located on the pivoting fin serving to limit the degree of pivot. These shoulders appear to be comprised of opposing springs whose resistance to pivot is determined by the spring material or spring constant, with a stiffer spring rendering the surfboard more stiff. In another embodiment, an insert comprised of a pair of wings provides the pivoting mechanism. The insert is disposed in a cavity between the pivot fin and the base. The stiffness of the hinge appears to be determined by the thickness of the insert. As in the prior embodiment, the pivot axis runs horizontally along a hinge pin located in a bore spanning the pivot fin, elastomeric member, and base. Side shoulders serve as stop members to limit the pivot of the pin. It does not appear that this surfboard fin assembly may be configured such that all pivoting is disabled. Furthermore, the pivot range of motion appears to be determined by either the spring material or shoulders positioned adjacent to the pivot mechanism. It is understood that neither of these elements is able to precisely control the degree of pivot within a narrow range of motion. Finally, this prior art pivot fin assembly does not appear to be specifically intended for use on a surfboard, nor does it appear to readily enable the adjustment of the pivoting mechanism.
Accordingly, there appears to be a need in the art for a new surfboard fin assembly intended specifically for surfboards that are able to accommodate all types of surfboard fins with a readily accessible and precisely adjustable pivoting mechanism that enables adjustment of the pivot of the fin blade within a narrow range.